In the prior art, there are countless formulations of toothpaste/dentifrice, attributed for improving of dental hygiene of the user. The known formulations include various types and concentrations of antibacterial agents, surfactants, fluoride components, abrasives, polymers, salts, oxidants, flavor compounds and other useful components for user teeth. Nevertheless most of the toothpastes with antibacterial components show relatively short antiseptic action due to intensive cleaning of the treated surfaces in the mouth by saliva and rapid reduction of the concentration of active component below minimal inhibiting concentration (MIC). In order to prolong action of the antiseptics toothpaste formulation containing antiseptic triclosan and maleic anhydride-vinyl methyl ether copolymer for improvement of antibacterial action (U.S. Pat. No. 5,192,531) was developed. The anionic character of the polymer makes impossible the use of the potent cationic antiseptics in this formulation.
Chlorhexidine incorporation into toothpaste composition is a problematic task due to formation of insoluble precipitates with common anions. Some of such compounds are patented, (U.S. Pat. No. 3,937,805); this approach was unsuccessful due to significant loss of antiseptic activity.
U.S. Pat. No. 5,130,122, describes a dental composition comprising oil-in-water submicron emulsion for dental use with improved customer properties. Although useful, this formulation has a relatively short retention time and rapid elimination from the mucous surfaces at the application. Sodium lauryl sulfate, needed for submicron emulsion preparation can cause irritation in gums and palate and is incompatible with cationic antibacterial substances, e.g., chlorhexidine salts or alkylammonium derivatives.
Another approach to extend the action of different agents is demonstrated in U.S. Pat. No. 5,744,155, where each droplet of the submicron emulsion is coated with polymer possessing pronounced mucoadhesive properties. Interaction of the polymer layer with mucosal surface leads to prolonged presence of the drug loaded lipid particle on the surface thus increasing time for local release of active compounds.
The present invention provides a pleasant tasting toothpaste composition providing long acting antibacterial and/or anti-caries action and method for its preparation.